1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display that is adaptive for minimizing a leakage current to prevent brightness deterioration.
2. Description of the Related Art
Generally, a liquid crystal display device is widely used due to its characteristics of light weight, thin profile, low power consumption, etc. As a result, the liquid crystal display device is used in office automation equipment, audio/video equipment, etc. The liquid crystal display device controls the amount of light in accordance with signals applied to a plurality of control switches that are arranged in a matrix to display a desired picture on a screen.
In this way, the liquid crystal display device is not a self luminous display device, thus it requires a separate light source such as a backlight unit.
The backlight unit is largely classified as an edge type and a direct type. Herein, the edge type backlight unit has a lamp which is installed at the end of one side of a liquid crystal display, and the direct type backlight unit has a lamp which is installed under the liquid crystal display.
FIG. 1 is a perspective view showing a rear surface of a related art liquid crystal display.
Referring to FIG. 1, a liquid crystal display with which the direct type backlight unit is applied, includes a plurality of lamps (not shown), an inverter circuit board 12 closely located at a rear surface of a bottom cover 10 and driving the lamps, and sockets 16 connecting lamp wires 14 to output terminals of the inverter circuit board 12. Herein, one end of the lamp wire 14 is connected to an electrode of the lamp.
The lamps are supplied with an AC power from the inverter circuit board 12 and emit a light. The inverter circuit board 12 is installed at the rear surface of the bottom cover 10 to convert a DC voltage into an AC voltage that is capable of driving the lamps, thereby outputting the AC voltage via the output terminal. The inverter circuit board 12 is also connected, via the sockets 16, to the lamp wires 14 connected to one ends of the lamps to apply the AC voltage to the lamps.
The lamp wires 14 are high-level voltage wires which are connected to the ends of the lamps. The lamp wires 14 are drawn out to the external of the bottom cover 10 via wire drawing out holes 18 and then are connected to the inverter circuit board 12 by the sockets 16. In this case, the wire drawing out holes 18 are formed at a support main. Herein, two lamp wires 14 are connected to one socket 16, respectively.
As described above, the lamp wires 14 must be drawn out toward the rear side of the bottom cover 10 to be connected to the inverter circuit board 12 so as to allow the inverter circuit board 12 to be electrically connected to the lamps. In this case, if a connection between the lamp wires 14 and the inverter circuit board 12 is tightened or is entangled each other, interference may be generated. To solve this problem, if a length of the lamp wire 14 is lengthened, an area that the lamp wire 14 is contacted with the bottom cover 10 made of a metal, is increased. As a result, an amount of the leakage current is increased.
Furthermore, a print circuit board 20 is located at an upper portion of the liquid crystal display. In this case, lengths of two lamp wires 14 connected to a first socket 16a are different from each other. Herein, the first socket 16a is formed at an upper corner where is closely located to the print circuit board 20. If the lengths of two lamp wires 14 are different from each other, the leakage current generated from each of the lamp wires 14 is differentiated. Thus, the brightness of the lamps changes and the screen blinks.